diff --git a/README.md b/README.md
index 673d0b2..ab91ab7 100644
--- a/README.md
+++ b/README.md
@@ -61,7 +61,7 @@ params:
   images:
     - images/og-featured.png # relative path to "static" directory
   customCSS:
-    - css/my.css # relative path to "assets" directory
+    - css/my.css # relative path to "assets" directory (don't use main.css filename)
   customJS:
     - js/main.js # relative path to "assets" directory
   dateFormat: "2006-01-02"